Fixed BUG#3287: Stored procedure handler scope outside of begin/end.

Backpatching overwrote already backpatched instructions, which made it
skip the hpop instruction; possibly not only a problem for handlers,
but this is one known case when it happened.

mysql-test/r/sp-error.result

@@ -295,7 +295,7 @@ create function bug1654()
 returns int
 return (select sum(t.data) from test.t2 t)|
 ERROR 0A000: Statements like SELECT, INSERT, UPDATE (and others) are not allowed in a FUNCTION
-drop table if exists table_1|
+drop table if exists t3|
 create table t3 (column_1_0 int)|
 create procedure bug1653()
 update t3 set column_1 = 0|
@@ -362,4 +362,28 @@ end case|
 call bug3287(2)|
 ERROR 20000: Case not found for CASE statement
 drop procedure bug3287|
+drop table if exists t3|
+create table t3 (s1 int, primary key (s1))|
+insert into t3 values (5),(6)|
+create procedure bug3279(out y int) 
+begin
+declare x int default 0;
+begin
+declare exit handler for sqlexception set x = x+1;
+insert into t3 values (5);
+end;
+if x < 2 then
+set x = x+1;
+insert into t3 values (6);
+end if;
+set y = x;
+end|
+set @x = 0|
+call bug3279(@x)|
+ERROR 23000: Duplicate entry '6' for key 1
+select @x|
+@x
+0
+drop procedure bug3279|
+drop table t3|
 drop table t1|

mysql-test/t/sp-error.test

@@ -400,7 +400,7 @@ return (select sum(t.data) from test.t2 t)|
 # BUG#1653
 #
 --disable_warnings
-drop table if exists table_1|
+drop table if exists t3|
 --enable_warnings
 create table t3 (column_1_0 int)|
 
@@ -500,6 +500,37 @@ end case|
 call bug3287(2)|
 drop procedure bug3287|
 
+
+#
+# BUG#3297
+#
+--disable_warnings
+drop table if exists t3|
+--enable_warnings
+create table t3 (s1 int, primary key (s1))|
+insert into t3 values (5),(6)|
+
+create procedure bug3279(out y int) 
+begin
+  declare x int default 0;
+  begin
+    declare exit handler for sqlexception set x = x+1;
+    insert into t3 values (5);
+  end;
+  if x < 2 then
+    set x = x+1;
+    insert into t3 values (6);
+  end if;
+  set y = x;
+end|
+
+set @x = 0|
+--error 1062
+call bug3279(@x)|
+select @x|
+drop procedure bug3279|
+drop table t3|
+
 drop table t1|
 
 delimiter ;|

sql/sp_head.cc

@@ -1144,10 +1144,12 @@ sp_instr_hpush_jump::print(String *str)
 {
   str->reserve(32);
   str->append("hpush_jump ");
+  str->qs_append(m_dest);
+  str->append(" t=");
   str->qs_append(m_type);
-  str->append(' ');
+  str->append(" f=");
   str->qs_append(m_frame);
-  str->append(' ');
+  str->append(" h=");
   str->qs_append(m_handler);
 }
 

sql/sp_head.h

@@ -351,7 +351,7 @@ class sp_instr_jump : public sp_instr
 public:
 
   sp_instr_jump(uint ip)
-    : sp_instr(ip)
+    : sp_instr(ip), m_dest(0)
   {}
 
   sp_instr_jump(uint ip, uint dest)
@@ -368,7 +368,8 @@ class sp_instr_jump : public sp_instr
   virtual void
   set_destination(uint dest)
   {
-    m_dest= dest;
+    if (m_dest == 0)		// Don't reset
+      m_dest= dest;
   }
 
 protected: